A better service can be provided to disabled persons if it can be detected that there is a disabled person who is using a wheelchair (hereinafter, “wheelchair user”) in an elevator cage. For example, if there is a wheelchair user in the elevator, the operation mode of the elevator may be changed from a normal operation mode, which is suitable for able-bodied persons, to a wheelchair operation mode, which is safer and more comfortable than the normal operation mode.
For example, in the wheelchair operation mode, the elevator cage may be operated at a lower speed, may be made to land more accurately and smoothly than that in the normal operation mode. When there is no wheelchair user in the elevator cage, the elevator cage may be operated at a faster speed and more roughly to give importance to the operating efficiency of the elevator than the safety or the comfort.
Conventionally, when a wheelchair user gets on an elevator, he/she pushes a button to change the operation mode from the normal operation mode to the wheelchair operation mode.
However, sometimes the wheelchair user may not be able to push the button, for example, when the elevator cage is full with passengers. Sometimes the wheelchair user may have to request someone to press the button for him/her. On the contrary, a child or even an adult able-bodied person may unknowingly or accidentally push the button to resultantly lower the operating efficiency of the elevator although there is no wheelchair user in the elevator cage. Thus, it will be more convenient if the normal operation mode can be changed to the wheelchair operation mode when there is a wheelchair user in the elevator cage.
To automatically change the operation mode, it is necessary to detect whether there is a wheelchair user in the elevator cage. One approach to detect whether there is a wheelchair user in the elevator is to use an image processor. A number counting apparatus that performs image recognition of passengers in an elevator is disclosed in, for example, Japanese Patent Application Laid-Open No. H6-92563, though it does not detect whether there is a wheelchair user in the elevator.
FIG. 14 is a block diagram of the number counting apparatus. The number counting apparatus includes an imaging unit 901, an image processing unit 902, a neural network 903, and a number determination unit 904. The imaging unit 901 is installed on the ceiling located above the passengers' heads so as to take pictures vertically downward, in the elevator cage or in the elevator hall.
First, an image of the situation in the elevator cage or in the elevator hall is captured by the imaging unit 901, and input to the image processing unit 902. FIG. 15 is an example of an image captured by the imaging unit 901. This image includes three persons 906 to 908. The image processing unit 902 generates a differential image by performing differential processing for performing binarization, based on an absolute value of a difference between respective pixel values, in the captured image and in the background image obtained by photographing the inside of the elevator cage or the elevator hall, in the state that there is no person therein, and clarifies a human region. The image processing unit 902 divides the binarized differential image into a plurality of blocks having different areas, calculates the proportion of the human region occupying in each block, and inputs the calculated result to the neural network 903 as input data.
The neural network 903, which has been allowed to learn beforehand, processes the input data, and the output signal is input to the number determination unit 904. The number determination unit 904 determines the number from the output signal from the neural network 903, and transmits or outputs the result to other controllers and the like according to the purpose.
However, because the image processor captures an image of a person from above, an image that is much smaller than when the image is captured from a side is obtained. Because the image is small, it cannot be used surely to determine whether the person in the image is a wheelchair user.
Moreover, number of persons can not be accurately distinguished if a few persons are standing close to each other. Because the persons can not be distinguished, it cannot be surely determine whether there is a wheelchair user.
It is an object of the present invention to provide an image processor that can distinguish persons, even if there are a plurality of persons standing close to each other, and can determine whether there is a wheelchair user.